As known in the art, when a wood working machine is to be operated, an adjustable featherboard structure such as that disclosed in U.S. Pat. No. 4,476,757 is required to fix the machine onto the working table for adjusting the forward and backward movements and clamping workpieces of various width in sawing operations. Then if a workpiece with a preset angle has to be sawn, a protractor or level is further needed. In other words, all these belong to single-function operations. Very often, various kinds of measuring instruments have to be prepared in doing a sawing job, otherwise, sawing cannot be proceeded. Moreover, these instruments occupy space and are not convenient to use; they may also be easily misplaced or lost.
In view of the aforesaid, improvement is needed to eliminate the above drawbacks in the prior art.